- Descent with modification was Darwin’s theory on how the Tree of Life was created
- Darwin accounted for extinction and inheritance but did not know about genes or DNA
- The mechanism proposed by Darwin was different from Lamarck
Evolution: Change in the genetic
composition of a population over
Human = ~27 years
Bacteria = ?
?Could new species arise from an ancestral form by adaptations to different environments?
homologous structures =
(1) Individuals in a population vary in their traits
trait is an observable and measurable characteristic of an organism phenotype
Trait variation comes from random mutations
(2) Some of these differences are heritable
(3) In each generation, many more offspring are produced than can survive
(4) Individuals with certain heritable traits are more likely to survive and reproduce ( adaptation)
If you were a bacteria today, in 2024….
Humans = ~25 years
Bacteria = ~20 minutes
How long is the average course of antibiotic treatment?
Do you now better understand new variants of SARS-CoV-2?